Added link to video of wave propagation in simple 2D intro example.

docs/source/screencasts.rst

@@ -4,9 +4,16 @@
 Screencasts
 ***********
 
-This section provides links to screencasts that explain how to install gprMax, demonstrate some of its key features, and give example models showing applications.
+This section provides links to screencasts and videos that explain how to install gprMax, demonstrate some of its key features, and give example models showing applications.
 
 Installation
 ------------
 
-* `How to install gprMax for end users on Microsoft Windows <https://youtu.be/dvC0_7qFVbE>`_ -- Needs updating for new unified installation procedure (30/05/2016)
+* `How to install gprMax for end users on Microsoft Windows <https://youtu.be/dvC0_7qFVbE>`_ -- Needs updating for new unified installation procedure (30/05/2016)
+
+Wave propagation
+----------------
+
+Using the ``#snapshot`` command and Paraview to visualise how the electromagnetic waves are propagating in a simulation.
+
+* `PEC cylinder buried in a lossless half-space <https://youtu.be/BpBo0-SFda4>`_